Haven't had a US phone in a while. I bought an Oppo, which doesn't use glass on the back, and now the Moto X Pure which you can pick what you want from wood or plastic.
I think makers that sell in other countries are more concerned about what customers do with phones. They have to be.
Some mfg is moving to India, and while not trying to diss India, they do have some laws which leave westerners scratching western heads. Africa, too. Wireless seems to be easier to install than wired, there. But a lot of these customers are probably a lot harder on their phones than we are. We have access to all kinds of protection. And we demand things which make the units larger.